When there is a "broken"/locked working copy, the subversion-plugin should normally delete the working copy and checkout a fresh one (source code).
But on our windows build agents the locked working copy is simply ignored and build continues.
There is no error logged indeed, but the checkout stops at this point.
I noticed the checkout being stopped because our repo consists of several externals and the last entry in checkout log contains the update for the locked external, but the remaining externals are not being updated.
This causes the working copy not being updated, so we are building an old version without recognizing it.
In addition this leads the scm trigger being fired again and again, because the old revision of the working copy is saved to the builds/jobs scm information.